The DC version of Vibranium, called Promethium, is a powerful substance that can direct any energy—including the Green Lantern's willpower construct—into a weapon that can effectively destroy the Justice League. It's a pity it's used by mercenaries named Death Knell, otherwise it would have really come in handy.
As Christopher Priest and Pete Wood saw in Justice League #43 of 2018, this issue serves as the finale of this particular volume of the Justice League, as DC's best head-to-head with Slade Wilson (aka the Terminator). With the power of his Promethium Blade and Titanium Staff, Deathstroke fought fierce battles against the heroes who desperately stopped him from dying on the road after he knocked out Superman, Aquaman, and others.
Soon facing the two Green Lanterns of Simon Buzz and Jessica Cruz, Death knell appears to have met his opponent on the battlefield. But after harnessing his ingenuity and existing equipment tailored for such occasions, the death knell proved that the Green Lantern could become an anti-Justice League weapon with the right help of villains like him. Slade easily shoots out green willpower with his promethium weapon with his promethium weapon. Saying that his sword "absorbs all forms of energy," The death knell confirms that all he has to do is direct the said energy into his titanium staff, redirecting it to his enemies, in the words of this skilled mercenary, "Green Team!" ”
A dangerous combination of weapons, the DC version of Vibranium can be reused to take out justice leagues effortlessly, which is a big problem for heroes who can usually easily cope with any problem they encounter. Add to that the fact that if Promethium is there, the Green Lanterns need to stay away from any and all members of the league because they might end up being used against teams (as shown, as they themselves are), and you have a powerful weapon that Deathstroke — and anyone with access to Promethium — can use in the worst possible way.
So, fortunately, while the amount of promethium isn't enough to make the tactic of the death knell something to worry about on a regular basis, it's still deadly enough when combined with the green lantern's energy. When promethium is nearby, The Green Lantern should always avoid the Justice League, or at least do their best to steer their constructs out of their weakened range.